WAUKESHA, Wis. (CBS 58) -- An 18-year-old Waukesha man is charged with homicide in his friend's death after an incident in Minooka County Park. 

An investigation revealed Daniel Lazaro was driving in the early morning hours of June 9, while his friend, also 18 years old, hung onto the exterior of the vehicle. The victim fell onto the paved parking lot while Lazaro was driving. 

The victim was taken to Waukesha Memorial Hospital and then transferred to Children's Wisconsin where he died the next day. An autopsy determined the victim's cause of death was blunt force trauma to the head, his injuries consistent with falling off a moving vehicle. 

Investigators interviewed another individual who was inside the vehicle at the time of the incident. They explained Lazaro, the victim, and three others went bowling on June 8, and afterward all got into a van and Lazaro drove them to Minooka County Park -- located on Sunset Drive.

While driving around the park, they stated one of the individuals in the car opened the sliding right side door of the van to "feel the air." The individual told investigators the victim proceeded to "partially hang outside of the van and was hanging on." 

Another individual in the car told investigators a similar story; the group was driving around and hanging out in Minooka Park and the victim was hanging out of the vehicle while holding on to the roof rack. They told officials the incident happened 10-15 minutes after they arrived at the park, and stated Lazaro was going about 20-25 mph when the victim fell. 

Immediately after the victim fell, the group got him back inside the van and drove him to the hospital. 

Investigators spoke with Lazaro, who admitted this was not the first time the group hung onto the outside of a vehicle and riding on it while driving. A search of his cellphone found two videos from May, 2019, showing the group riding on the outside of an SUV-type vehicle. Also in the video, investigators said it appeared the individuals were passing around a device to smoke from while riding around. 

Authorities determined Lazaro received his probationary driver's license on June 3, the week prior to the incident. 

Lazaro has been charged with one count of homicide by negligent operation of a vehicle. If convicted, he could spend up to ten years in prison.